A Phase II Study of Erlotinib in Patients with Previously Treated Non-Small Cell Lung Cancer

Background: Erlotinib has been reported to be effective for the treatment of non-small cell lung cancer (NSCLC). To evaluate the efficacy and safety of erlotinib under conditions similar to daily clinical practice, a phase II trial was conducted in Japanese patients with previously treated NSCLC. Methods: The eligibility criteria were stage IIIB/IV NSCLC, a performance status (PS) of 0 - 2, and previous treatment with 1 - 2 non-EGFR-TKI regimens. Patients received erlotinib (150 mg/day) orally until disease progression or intolerable toxicity occurred. The primary endpoint was the objective response rate (ORR). In addition, the disease control rate (DCR), progression-free survival (PFS), overall survival (OS), safety, and EGFR gene mutation status were evaluated. Results: Thirty-eight patients were enrolled, and 37 patients were evaluated. The median age was 69 years (range, 50 - 80 years). Patient characteristics were as follows: 26 were male and 11 were female; 12 had a PS of 0, 20 had a PS of 1, and 5 had a PS of 2; and 26 had adenocarcinoma, and 11 had non-adenocarcinoma histology. The ORR and DCR were 21.6% (95% confidence interval [CI], 11.4% - 37.2%) and 54.1% (95% CI, 35.9% - 66.6%), respectively. Twenty-seven patients could be evaluated for EGFR gene status (12, mutated; 15, wild-type). The ORR for EGFR-mutated patients was 41.7%, while that for patients with wild-type EGFR was 13.3%. The median PFS was evaluated as 4.4 months (95% CI, 2.2 - 10.7 months). The median OS was 14.9 months (95% CI, 9.2 months - not reached). Common adverse events were tolerable skin toxicities, diarrhea, and stomatitis. In addition, interstitial lung disease occurred in 8.1% of patients. Conclusion: As efficacy and safety were similar to previous studies, erlotinib was found to be effective for Japanese patients with previously treated NSCLC in clinical practice.